1. Field of the Invention
The present invention relates to a system, a device and a program, and a method for controlling access to a plurality of network printers, and particularly relates to an access control system, an accessed terminal, an access terminal and a program for terminal, and an access control method suitable for inhibiting an increase in communication traffic and preventing an excessive process load applied to certain terminals and certain devices.
2. Description of the Related Art
Hitherto, for example, a printer management system shown in FIG. 40 has been used as a technique for collecting status information from a plurality of network printers by a printer management server.
FIG. 40 is a block diagram showing a configuration of a conventional printer management system.
As shown in FIG. 40, a printer management server 100 managing network printers 200 and a plurality of routers 110 are connected to the Internet 199. A plurality of network printers 200 and the printer management server 120 managing those network printers 200 are connected to each router 110, and the network printers 200 and the printer management server 120 are connected to the Internet 199 via the router 110. In addition, the router 110, the network printers 200 and the printer management server 120 constitute one sub-network 198. The sub-network 198 is established for each company, for example.
The network printer 200 is managed by the printer management server 120 of the sub-network 198 to which the network printer 200 itself belongs. Status information is periodically generated, and the generated status information is stored in a storage device. In addition, when a status information acquirement request is received, status information in the storage device is sent to the printer management server 120.
The printer management server 120 manages network printers 200 of the sub-network 198 to which the printer management server 120 itself belongs. The status information acquirement request is sent to each network printer 200 at predetermined intervals and when status information is received, the received status information is stored in a status information registration database (hereinafter, database is abbreviated simply as DB) for each network printer 200. In addition, status information in the status information registration DB is sent to a printer management server 100 at predetermined intervals.
The printer management server 100 manages printer management servers 120. When status information is received, the received status information is stored in a storage device for each network printer 200.
Furthermore, other techniques related to such a printer management system include, for example, a method for maintenance of printing device disclosed in Japanese Patent Laid-Open No. 8-161134 (hereinafter referred to as first exemplary conventional technique).
In addition, techniques for dynamically changing a server include, for example, a network system disclosed in Japanese Patent Laid-Open No. 2000-181653 (hereinafter referred to as second exemplary conventional technique).
In the second exemplary conventional technique, a first server designates an alternative server as a second server based on alternative server selection conditions in a device information table. Management information (device information table, performance information table) stored in the first server, an accumulated reference D2 (print request) and print data D1 are sent to a second server to make a replacement request the second server. The second server updates management information of the second server based on management information sent from the first server. In addition, the reference D2 sent from the first server, and print data D1 are stored in a spool. Then, the second server notifies a workstation that the server to which the print data D1 and reference D2 are sent has been changed to the second server, and notifies printers that the server acquiring print data D1 has been changed to the second server.
Consequently, the alternative server can be dynamically selected to continuously carry out print processing even if a failure occurs in the server.
However, the conventional printer management system described above has a problem such that because printer management servers 120 send status information in a status information registration DB to a printer management server 100 at predetermined intervals, access by a plurality of printer management servers 120 may be focused on the printer management server 100 to cause an increase in communication traffic and apply an excessive process load to the printer management server 100.
In addition, the conventional printer management system described above has a problem such that because the printer management server 120 is provided for each sub-network 198, costs and time and efforts are required for introduction and maintenance of the printer management server 120. The first and second exemplary conventional techniques have the same problem in the sense that servers should be provided.
Furthermore, the second exemplary conventional technique has a problem such that a certain server selects an alternative server, and therefore in case where a failure occurs in the certain server before replacement of the server, or a failure occurs in the certain server and the alternative server after replacement of the server, print processing may stop, and thus reliability against failures is insufficient.
Furthermore, the problem is not limited to the network printer, but can be anticipated for network devices other than the network printer.
The present invention has been made in consideration of such unsolved problems of conventional techniques, and has as its fist object the provision of an access control system, an accessed terminal, an access terminal and a program for terminal, and an access control method suitable for inhibiting an increase in communication traffic and preventing an excessive load applied to certain terminals and certain devices. In addition, the present invention has as its second object the provision of an access control system, an accessed terminal, an access terminal and a program for terminal, and an access control method suitable for reducing costs and time and efforts and improving reliability.